So those rural farmers who had little to begin with were "taken care of" by the government during their time of need? If you think that you will be happy with the "good of the people" that will be enforced by the government during times of national emergency then you should look into what their contingency plans are and try your best to ensure that you are among the people for whom the "good of the people" applies. These folks probably didn't know that their government had a contingency plan that included flooding out their farms and livelyhoods and even entire towns in order to save the city folks. Think about it. What is the fema plan in your state when the nuke plant a hundred miles away melts down? Are you going to have thousands of refugees living at your high-school all of a sudden? Disasters that happen quite far away can have a direct impact on your preparations and plans or they can surprise you with the impact because you didn't lookup the plans and prepare for them. Either way, distant events will directly impact your life and survival.

If you live in a flood plain, even one that is protected by human artifact, move. If you feel you have a reason that requires you to live in a flood plain change it. The only preparation for flood is to be absent when the water rises.